1. Field of the Invention
The present invention relates to a device and method for chemical processing of a biological sample, and more particularly to a self-aliquoting sample dispensing assembly. The dispensing assembly, which comprises a dispensing unit and a storage unit, has a plurality of receptacles and is capable of dispensing a sample substantially simultaneously into each of the plurality of receptacles. The dispensing assembly is well suited for dispensing samples for subsequent high throughput screening, and is particularly useful for dispensing, storing and transporting biological samples for subsequent clinical analysis.
2. Description of Relevant Art
Presently, across a broad range of technology-based business sectors, including the chemical, bioscience, biomedical, and pharmaceutical industries, it has become increasingly desirable to develop capabilities for rapidly and reliably carrying out chemical and biochemical reactions in large numbers using small quantities of samples and reagents. Carrying out a massive screening program manually, for example, can be exceedingly time-consuming, and may be entirely impracticable where only a very small quantity of a key sample or component of the analysis is available, or where a component is very costly.
In order to perform this function effectively, systems and methods have been developed for accurate and rapid dispensing of liquid samples and/or reagents, for example into multi-well plates. Typical multi-well plates contain 96, 192, 384, or 1536 receptacles which must be filled with a predetermined amount of a liquid sample.
Conventional pipettes are known which can accurately dispense a known quantity of liquid sample into a receptacle or other container. Manual pipettes have the obvious limitation of requiring sequential operation which is time consuming and inefficient. More automated devices, such as multi-channel pipetters are commercially available and represent an improvement over manually operated pipettes. In one example, a 96 channel pipetting device using positive displacement plungers in corresponding cylinders to draw in and expel liquid via a sampling/mltering step is known. Devices of this type are often complicated mechanisms and can be prone to problems in regulating the amount of liquid dispensed, controlling splashing, maintaining sterility, and the like.
In clinical diagnostic settings, it has often been necessary to collect biological samples such as whole blood, red blood cell concentrates, platelet concentrates, leukocyte concentrates, bone marrow apirates, plasma, serum, cerebral spinal fluid, feces, urine, cultured cells, saliva, oral secretions, nasal secretions and the like in various containers or tubes for subsequent testing and analysis. Typically, the samples must then be transported to a different location, such as a laboratory, where personnel conduct specific tests on the samples. Specific tests include experiments such as, for example, protein quantification, 2-D gel plotting of proteins, drug development, Western blotting, reporter gene analysis, immunoprecipitations, epitope tagging, specific protein activity assays, etc.
It is very desirable to rapidly detect and quantify one or more molecular structures in a sample. The molecular structures typically comprise ligands, such as antigens and antibodies. Ligands are molecules that are recognized by a particular receptor. Ligands may include, without limitation, agonists and antagonists for cell membrane receptors, toxins, venoms, oligosaccharides, proteins, bacteria and monoclonal antibodies. For example, cell and antibody detection is important in numerous disease diagnostics. In recent years there has been an increase in interest in the field of biological, medical and pharmacological science in the study of nucleic acids obtained from biological samples. For example, DNA or RNA sequence analysis is very useful in genetic and infectious disease diagnosis, toxicology testing, genetic research, agriculture and pharmaceutical development. In particular, genomic DNA (gDNA) isolated from human whole blood can provide extensive information on the genetic origin and function of cells. This information may be used in clinical practice, e.g., in predisposition testing, HLA typing, identity testing, analysis of hereditary diseases and oncology. The gDNA is analyzed via many molecular diagnostic downstream procedures (e.g., micro-array analysis, quantitative PCR, real time PCR, Southern Blot analysis, etc).
In particular, nucleic acid-based analyses often require sequence identification and/or analysis such as in vitro diagnostic assays, high throughput screening of natural products for biological activity, and rapid screening of perishable items such as donated blood or tissues, for a wide array of pathogens. There has been a convergence of progress in chemistry and biology. Among the important advances resulting from this convergence is the development of methods for identifying molecular diversity and for detecting and quantifying biological or chemical material. This advance has been facilitated by fundamental developments in chemistry, including the development of highly sensitive analytical methods, solid-state chemical synthesis, and sensitive and specific biological assay systems. For example, Sanger Sequencing, blotting techniques, microplate assays, polymerase chain reaction, hybridization reactions, immunoassays, combinatorial libraries, proteomics and the like.
Traditional medical lab tests for biological samples require that the sample be obtained, transferred to a collection tube and then sent to a lab for analysis. Clinical analysis often requires the use of systems for metering, dispensing and mixing reagents with sample fluids. The sample fluids may include, for example, tissue samples, blood samples, urine samples or minute quantities of deoxy ribonucleic acid (hereinafter “DNA”) sequences in a buffer fluid. Both manual and automated systems have been available for aliquoting the fluid samples and assaying the samples with one ore more reagents. Manual systems have historically included the glass capillary pipette, the micropipette, precision syringes and weighing equipment. A variety of biological assays have been and continue to be conducted with manual equipment of the type described.
Typical methodologies, which require that the sample be distributed in a serial manner, are cumbersome. There remains a need for an apparatus and method capable of distributing a fluid sample to multiple containers evenly by a single process at the same time.
Thus, there is a present need for an automated system capable of dispensing a predetermined amount of liquid into multi-well plates and the like which is accurate, quick, and if required, preserves the sterility of the sample being dispensed for processing and/or storage.